Method for controlling vehicular electric system

• US 7,657,438 B2
• Filed: 02/24/2004
• Issued: 02/02/2010
• Est. Priority Date: 02/25/2003
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Tani, Keisuke, Obayashi, Kazuyoshi
• Primary Examiner(s): Hayes; John W
• Assistant Examiner(s): Clark; David J
• Application Number:
  US10/784,273
• Publication Number:
  US 20040164616A1
• Time in Patent Office: 2,170 Days
• Field of Search: 705/1, 705/400, 903/903, 903/907, 320/104, 320/130
• US Class Current: 705/1.1
• CPC Class Codes: B60K 6/46 Series type
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2210/12 Buck converters
• CPC Class Codes: B60L 2210/14 Boost converters
• CPC Class Codes: B60L 3/12 Recording operating variables ; Monitoring of operating variables
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60L 50/62 charged by low-power generators primarily intended to support the batteries, e.g. range extenders
• CPC Class Codes: B60L 53/20 characterised by converters located in the vehicle
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60L 58/20 having different nominal voltages
• CPC Class Codes: B60L 58/25 by controlling the electric load
• CPC Class Codes: B60L 7/12 for vehicles propelled by dc motors
• CPC Class Codes: B60T 1/10 by utilising wheel movement for accumulating energy, e.g. driving air compressors
• CPC Class Codes: B60T 13/586 the retarders being of the electric type
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/18 including control of braking systems
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/13 in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: B60W 2050/0025 Transfer function weighting factor
• CPC Class Codes: B60W 2510/244 : Charge state
• CPC Class Codes: G06Q 30/0283 : Price estimation or determination
• CPC Class Codes: H02J 2207/40 : adapted for charging from various sources, e.g. AC, DC or multivoltage
• CPC Class Codes: H02J 2310/48 : for electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: H02J 7/1438 : in combination with power supplies for loads other than batteries
• CPC Class Codes: Y02T 10/40 : Engine management systems
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y02T 10/84 : Data processing systems or methods, management, administration
• CPC Class Codes: Y02T 90/12 : Electric charging stations
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles
• CPC Class Codes: Y10S 903/903 : having energy storing means, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/907 : Electricity storage, e.g. battery, capacitor

Abstract

A method for controlling a vehicular electric system having multiple power sources including an engine-driven generator. The power sources for supplying power to charge an onboard battery are determined based on difference between the power generation cost of each power source and that for generating an amount of power charged in the battery. Furthermore, amounts power to be supplied to the battery 103 for charge is determined based on the amount of power currently charged in the battery.

Claims

1. A method for controlling a vehicular electric system having a plurality of power sources that supplies power to an onboard electrical load and an onboard battery, wherein the plurality of power sources includes at least one of a generator driven by an engine of a vehicle, a regenerative braking system, and an external source, the vehicular electric system including a power supply control device that controls power distribution from each of the power supplies, the battery having a storage capacity of a plurality of hypothetical energy units, the method comprising:

storing, by the power supply control device, a cost of generation for each unit of charge stored in the battery;

obtaining, by the power supply control device, information that includes, for each power source, a power generation cost that is an amount corresponding to fuel consumption for generating unit electrical power by the power source, the information further including information on an energy cost of the onboard battery based on charge and discharge histories of the onboard battery, the charge and discharge histories of the onboard battery including, for each unit of charge stored in the battery, the generation cost of the unit of charge;

determining a current cost of the battery from the costs of generation corresponding to the units of charge stored in the battery;

determining an amount of power that needs to be supplied;

calculating, by the power supply control device, a quota for power distribution for each of the power sources and the batten from the power generation costs of the power sources and the current cost of the battery; and

adjusting a power supply distribution of the plurality of power sources, a receiving power rate of the onboard electrical load, and one of a power supply distribution of the onboard battery and a receiving power rate of the onboard battery to reduce a consumed power cost,

wherein the adjusting is based on the information and performed by prioritizing a power supply from one of the plurality of power sources which has a lowest power generation cost of the plurality of power sources.

2. The method for controlling the vehicular electric system according to claim 1,

wherein the adjusting power supply distribution is performed based on the power generation cost of each power source and available power supply from each power source.

3. The method for controlling the vehicular electric system according to claim 1, further comprising:

controlling a power generation of each power source based on the power supply distribution; and

outputting an instruction signal to a device that supplies power to the plurality of power sources for controlling an output of the device based on the power supply distribution.

4. The method for controlling the vehicular electric system according to claim 1, further comprising:

determining the power supply distribution of the plurality of power sources to the onboard battery based on the information.

5. The method for controlling the vehicular electric system according to claim 4,

wherein the power supply from the one of the plurality of power sources which has the lowest power generation cost of the plurality of power sources, is prioritized when the onboard battery is charged.

6. The method for controlling the vehicular electric system according to claim 4,

wherein the plurality of power sources includes an engine of a hybrid vehicle and a regenerative braking system.

7. The method for controlling the vehicular electric system according to claim 6,

wherein the power supply of regenerative electric power supplied by the regenerative braking system is prioritized when the onboard battery is charged.

8. The method for controlling the vehicular electric system according to claim 4,

wherein the adjusting the power supply distribution for supplying power to the onboard battery is performed in accordance with a difference between the power generation cost of the onboard battery as one of the power sources and the power generation cost of another power source that supplies power to the onboard battery.

9. The method for controlling the vehicular electric system according to claim 8,

wherein the adjusting the power supply distribution for supplying power to the onboard battery is performed based on the difference between the costs and a state of charge of the onboard battery.

10. The method for controlling the vehicular electric system according to claim 9,

wherein the state of charge of the onboard battery is determined using an amount of power charged in the onboard battery and a variation in the amount of power.

11. The method for controlling the vehicular electric system according to claim 4, further comprising:

calculating and preferentially distributing a part of power supplied from the power sources to the electrical load; and

calculating and distributing the other part of power to the onboard battery, the other part supplied from the power sources after the distribution to the electrical loads.

12. The method for controlling the vehicular electric system according to claim 1, further comprising:

transferring power between the vehicle electric system and another vehicle electric system in such a manner that voltage of the another vehicle electric system is converted to voltage of the vehicle electric system, wherein the voltage of the another vehicle electric system is different from the voltage of the vehicle electric system.

13. The method for controlling the vehicular electric system according to claim 1, further comprising:

obtaining the information concerning a power generation cost of the generator driven by the engine of the vehicle based on engine efficiency at an engine operating point.

14. The method for controlling the vehicular electric system according to claim 13, further comprising:

correcting the power generation cost based on information of generator efficiency.

15. The method for controlling the vehicular electric system according to claim 13,

wherein the power generation cost of the generator driven by the engine of the vehicle is determined based on an increase in consumed fuel for driving the engine due to the power generation.

16. The method for controlling the vehicular electric system according to claim 1,

wherein the cost is defined by one of fuel weight, fuel volume, CO₂ generation amount, fuel price, and their combination.

17. The method for controlling the vehicular electric system according to claim 1,

wherein the cost is defined by an equation of (a unit fuel price)×

(fuel consumption per unit power)×

(generator efficiency).